Refrigerant pump with rotors in bearing

Abstract

A refrigerant pump includes a thin-walled hermetic vessel and a thick-walled hermetic vessel having an end inserted into and secured to an end of the thin-walled hermetic vessel. A stator of an electric motor unit is fitted outside the thin-walled hermetic vessel, while a rotor of the electric motor unit is accommodated inside the thin-walled hermetic vessel. A pump mechanism is fitted inside the thick-walled hermetic vessel, and a rotational force of the rotor is transmitted to the pump mechanism by the drive shaft.

1. A refrigerant pump comprising:
 a thin-walled hermetic vessel; 
 a thick-walled hermetic vessel having an end inserted into and secured to an end of the thin-walled hermetic vessel; 
 an electric motor unit having a rotor and a stator, the stator being fitted outside the thin-walled hermetic vessel while the rotor is accommodated inside the thin-walled hermetic vessel; 
 a pump mechanism fitted inside the thick-walled hermetic vessel; 
 a drive shaft for transmitting a rotational force of the rotor to the pump mechanism; 
 a suction plate having a suction port defined therein so as to extend completely through the suction plate and also having a discharge port defined therein so as to extend towards a longitudinal axis of the drive shaft, the suction port being of a generally crescent shape having a final suction port positioned at a lower end of the pump mechanism, wherein the drive shaft has a through-hole defined therein so as to extend in alignment with the longitudinal axis of the drive shaft, and the through-hole in the drive shaft and the discharge port are communicated with each other to define a refrigerant passage; and 
 a cylinder bearing of one-piece construction, wherein the pump mechanism comprises an outer rotor and an inner rotor in mesh with each other, the cylinder bearing having a pump-side bearing and a cylinder accommodating the outer rotor and the inner rotor therein, the drive shaft being supported by the cylinder bearing.